Chinese President Xi Jinping says his country will invest an additional one billion dollars into a fund to support developing countries.

He made the announcement on Friday at an expanded meeting of the five-nation group known as BRICS. The countries are Brazil, Russia, India, China and South Africa.

Chinese media say the leaders of 13 emerging and developing countries, including Indonesia, Iran and Egypt, attended the online meeting hosted by China.

Xi said Beijing will add one billion dollars to the existing 3 billion dollars for the fund established by China to promote cooperation among developing nations.

In an apparent attack on Western sanctions against Russia over its invasion of Ukraine, Xi was quoted by China's Foreign Ministry as saying certain nations are imposing "maximum sanctions, and deliberately creating division and confrontation".

Xi added that emerging and developing nations are more resolved to seek strength through unity, as the North-South gap keeps widening.

Xi also said China will cooperate in increasing production capacity for grain and other crops. The pledge comes amid growing concerns about a global food crisis due to the Russian blockade of Ukrainian exports.

Xi appeared to be touting Beijing's cooperation with developing countries ahead of a series of summits of Western nations, including a G7 summit scheduled to start on Sunday.